Hadith 1:682

Narrated Abu Huraira:

Once Allah's Apostle prayed two Rakat (instead of four) and finished
his prayer. Dhu-l-yadain asked him whether the prayer had been reduced
or whether he had forgotten. Allah's Apostle asked the people whether
Dhu-l-yadain was telling the truth. The people replied in the
affirmative. Then Allah's Apostle stood up, offered the remaining two
Rakat and then finished his prayer with Taslim and then said, "Allahu
Akbar." He followed it with two prostrations like ordinary
prostrations or a bit longer.